4. The composition of claim 1 wherein the composition further comprises
urea.

5. The composition of claim 1 wherein the composition retains
antimicrobial activity after twenty-five insults of E. coli as measured
by a log 2 reduction in organisms upon the twenty-fifth insult of
10.sup.6 total organisms.

[0003] In order to protect health and maintain hygiene, a variety of
environments require controlled and limited microbial growth. Such
environments include temporary and permanent healthcare facilities,
caregiver facilities (e.g., daycares, nursing homes, etc.) and
households. When growth of potentially harmful microbes is not
controlled/limited in these environments, the risk of infection and
spread of disease increases. Infection and disease may compromise the
health and safety of humans and/or animals occupying these environments.
While potentially not as sensitive as the above-identified environments,
workplace and public environments may also be negatively impacted by
uncontrolled/unlimited growth of disease-causing microbes.

[0004] Some types of microorganisms (bacteria, viruses, fungi, etc.) are
capable of negatively impacting the health and/or safety of living
organisms. Such microorganisms can be transmitted by contact with
surfaces on which the microorganisms are present and/or multiplying and
by contact between humans/animals already infected with particular
microorganisms. When such microorganisms spread and infect new "hosts",
the "host" can either go from an otherwise healthy state to a state of
illness or from a "compromised" state (i.e., a state of pre-existing
illness or a weak immune system) to a more serious/severe state. The
public health impact of the undesired spread of microorganisms is
significant as reflected by time out of school, time away from work
(either for self or to care for others not able to care for themselves),
additional time for which professional health care is needed, etc.
Therefore, it is desirable to be able to prevent or inhibit microbial
presence/growth on targeted surfaces. The presence of microorganisms can
be eliminated/controlled using surface treatments that may be applied
directly (as from a spray bottle) and by using wipes or other carriers
that include the surface treatment. Further, it is desirable that such
surface treatments have durability and persistence so that they do not
need to be re-applied on a frequent basis.

[0005] There are many detergent, disinfectant, cleaning and antimicrobial
compositions known in the art for killing and preventing growth of
microorganisms. These compositions include components/ingredients that
are well-known for antimicrobial functionality. For example, quaternary
ammonium compounds are considered "broad spectrum" antimicrobial cationic
compounds that are effective against both Gram positive (e.g.,
Staphylococcus species) and Gram negative (e.g., Escherichia coli)
microorganisms. Other components/ingredients that may be incorporated
into products for removing/reducing microorganisms on surfaces include
alcohols, acids and bleaching agents, such as hydrogen peroxide. Not all
of the antimicrobial components can be used at the same time because some
of them form unstable combinations.

[0006] Disinfecting and cleaning compositions that provide antimicrobial
activity over a period of time are also known in the art. For example,
U.S. Pat. No. 6,270,754 issued to Zhou et al. and entitled "Antimicrobial
Cleaning Composition" (hereinafter "the '754 patent") is directed to an
antibacterial cleaning composition that exhibits germicidal activity for
sustained periods of time. The '754 patent discloses an aqueous cleaning
composition that includes a quaternary ammonium compound, an anionic
polymer (where the anionic polymer has an acid number greater than 10 and
the anionic polymer is partially or completely neutralized by the
quaternary ammonium compound to form a polymer complex), a dispersing
agent and/or a water-miscible solvent. The aqueous cleaning composition
of the '754 patent has antibacterial activity against both Gram positive
and Gram negative bacteria. However, the components of the '754 patent
may not be effective against a broader range of microorganisms, such as
non-enveloped viruses.

[0007] In addition to the composition of the '754 patent, there are
compositions known in the art that are effective against a broad spectrum
of microorganisms and continue to have activity for a period of time. For
example, U.S. Pat. No. 7,598,214 issued to Cusack et al. and entitled
"Disinfecting Compositions Containing A Polymer Complex Of an Organic
Acid" (hereinafter "the '214 patent") is directed to compositions that
include at least one organic acid and at least one polymer capable of
forming a complex with the at least one organic acid. The compositions of
the '214 patent may also optionally include an anionic surfactant and an
organic acid. The organic acid may be citric acid and examples of
suitable polymers include vinylpyrrolidone/dimethylaminoethylmethacrylate
copolymer, vinylpyrrolidone/vinylacetate copolymers,
vinylpyrrolidone/vinylcaprolactum/ammonium derivative terpolymers and
polyvinylpyrrolidone. The compositions of the '214 patent need an organic
acid and they are pH sensitive. Because of the acid-based reaction
between the polymer having a tertiary amine functionality and the organic
acid, the compositions are not effective in higher pH environments. In a
higher pH environment, the reaction would reverse and the polymer would
be rendered ineffective because it would be neutral. Though the
compositions of the '214 patent are effective against a broader spectrum
of microorganisms, the compositions may not be effective against the
spore-form of all microorganisms because the compositions cannot
penetrate through the outer wall of the spores.

[0008] While many antimicrobial compositions are known and while some of
those compositions maintain their antimicrobial activity over a period of
time, there remains a need in the art for a durable antimicrobial
composition that is effective against a broad range of microorganisms,
including the spore-form of potentially harmful microorganisms.
Additionally, there remains a need for a durable antimicrobial
composition that is stable (i.e., is not reactive) so that it is not
unnecessarily harsh (causing wear or corrosion) on the surfaces on which
it is used. Further, there remains a need for a durable antimicrobial
composition that does not require a volatile solvent that may have an
unpleasant smell.

[0009] Furthermore, there is a need to provide a durable antimicrobial
composition that includes a stable surfactant such that cleaning is
achieved and also provides a composition wherein a long-lasting biocide
effect is maintained, rapid broad spectrum germicidal properties are
maintained, and multiple fragrances can be employed for consumer
acceptance.

SUMMARY

[0010] Durable antimicrobial compositions that are effective against a
broad range of potentially harmful microorganisms and that do not have to
be reapplied on a frequent basis to the surfaces on which controlled
microbial growth is desired are described herein. The durable
antimicrobial compositions are effective against a broad range of
microorganisms, including the spore-form of microorganisms, because of
the compositions components, which are unexpectedly stable in combination
with each other. Additionally, the durable antimicrobial compositions do
not need to contain a volatile solvent that could make the compositions
unpleasant to use. Additionally, the compositions need to include a
surfactant to provide a cleaning benefit without losing efficacy or the
long-lasting benefit of the compositions.

[0011] In one aspect, the compositions have durable antimicrobial activity
and include a carbonate/bicarbonate salt of a quaternary ammonium cation,
an organic acid, hydrogen peroxide, a surfactant and a polymer. The
polymer is selected from cationic amine polymer-epichlorohydrin adduct,
cationic amine polymer-epichlorohydrin resin,
poly(methacrylamidopropyltrimethylammonium) chloride,
poly(bis(2-chloroethyl)ether-alt-1,3-bis(dimethylamino)propyl)urea,
poly(diallyldimethylammonium)chloride, poly(t-butyl acrylate co-ethyl
acrylate co-methacrylic acid), polyethylene oxide, polyquaternium-16,
polyquaternium-22, polyquaternium-67, and mixtures of such polymers. As
described herein, the compositions have a durable or persistent activity
to kill and prevent the growth of potentially harmful microorganisms. The
durability of the compositions is indicated by the compositions retaining
antimicrobial activity after twenty-five insults of E. coli organisms as
measured by a log 2 reduction in organisms upon the twenty-fifth insult
of 106 total organisms. The durable antimicrobial compositions are
stable; the stability of the compositions is reflected by the
compositions maintaining their efficacy during shelf-life studies. For
example, the compositions remain effective (meaning, they have the same
level of durability to effect a log 2 reduction in organisms after
twenty-five insults of 106 organisms) after storage for three months
at 40° C.; further, the compositions remain effective after
storage for one month at 50° C., nine months at 25° C. and
after three freeze-thaw cycles. The compositions are liquid at room
temperature and can be applied directly to a surface for which it is
desired to prevent or inhibit microbial growth. The compositions may be
applied using a spray bottle or other known structure for dispensing
liquids. Alternatively, the compositions may be applied to a surface by
transfer from a basesheet, such as a wiper, into which a representative
composition has been incorporated. The basesheet may be made of a
nonwoven material or of a cellulosic material. More particularly, the
composition may include from 0.2 to 15.0 percent by weight of the
carbonate/bicarbonate salt of a quaternary ammonium cation. The
composition may include from 0.1 to 3.0 percent by weight of the organic
acid, which may be selected from citric, malic, maleic, oxalic, glutaric,
succinic, lactic, glycolic, fumaric, acetic, benzoic, propionic, sorbic,
tartaric, formic, and mixtures of such organic acids. The composition may
include from 0.5 to 5.0 percent by weight of hydrogen peroxide and the
composition may include from 0.5 to 10.0 percent by weight of polymer.

[0012] These aspects and additional aspects of the invention will be
described in greater detail herein. Further, it is to be understood that
both the foregoing general description and the following detailed
description are exemplary and are intended to provide further explanation
of the invention claimed.

DETAILED DESCRIPTION

[0013] The present disclosure of the invention will be expressed in terms
of its various components, elements, constructions, configurations,
arrangements and other features that may also be individually or
collectively referenced by the term, "aspect(s)" of the invention, or
other similar terms. It is contemplated that the various forms of the
disclosed invention may incorporate one or more of its various features
and aspects, and that such features and aspects may be employed in any
desired, operative combination thereof.

[0014] It should also be noted that, when employed in the present
disclosure, the terms "comprises", "comprising" and other derivatives
from the root term "comprise" are intended to be open-ended terms that
specify the presence of any stated features, elements, integers, steps,
or components, and are not intended to preclude the presence or addition
of one or more other features, elements, integers, steps, components, or
groups thereof.

[0015] Compositions having durable antimicrobial activity are disclosed
herein. The compositions may be used to kill or to inhibit the growth of
microorganisms that are potentially harmful or capable of causing
disease. The durable antimicrobial compositions do not need to contain a
volatile solvent and therefore, do not generate an unpleasant smell when
used. The compositions are effective at killing and/or inhibiting growth
of a broad range of microorganisms. For example, the compositions are
effective against both Gram positive and Gram negative bacteria.
Additionally, the compositions are effective against viruses, fungi,
mildew and mold. Further, the compositions are effective against bacteria
that form spores, bacteria with waxy outer layers, fungi that form spores
(fungal spores) and enveloped and non-enveloped viruses. Without wishing
to be bound by theory, it is believed that the compositions are capable
of breaking down the waxy outer layer of a bacteria or outer layer of a
spore so that the compositions can penetrate into the microorganism
beyond the outer layer.

[0016] The durable antimicrobial compositions may be used to control
microbial growth on a variety of surfaces, including relatively durable
objects having both hard and soft surfaces; for example, appropriate
surfaces may include door knobs, light switches, countertops, sinks, wash
basins, telephones, keyboards, remote controls, medical instruments,
upholstery, curtains, bedspreads, towels and shoes. The compositions may
be applied to the targeted surface either directly, in liquid form, such
as by a spray bottle or similar packaging capable of delivering a liquid
composition in a relatively uniform amount over the full surface to be
covered. Alternatively, the composition may be applied to the targeted
surface by a carrier, such as a basesheet (i.e., a "wet" wipe or wiper).
Because the compositions are liquid at room temperature, the composition
may be applied to a surface by wiping the surface with a basesheet that
has been saturated with the composition; the composition will transfer
from the basesheet to the surface. The basesheet may be formed from one
or more woven materials, nonwoven materials, cellulosic materials, and
combinations of such materials. More specifically, the basesheet may be
formed of nonwoven fibrous sheet materials that include meltblown,
spunlace, coform, air-laid, bonded-carded web materials, hydroentangled
materials, and combinations of such materials. Such materials can be made
of synthetic or natural fibers or a combination of such fibers.
Typically, the basesheet will have a basis weight of from 25 to 120 grams
per square meter and desirably from 40 to 90 grams per square meter.

[0017] The basesheet may be constructed of a coform material of polymer
fibers and absorbent fibers having a basis weight of from 45 to 80 grams
per square meter and desirably 60 grams per square meter. Typically, such
coform basesheets are constructed of a gas-formed matrix of thermoplastic
polymeric meltblown fibers and cellulosic fibers. Various suitable
materials may be used to provide the polymeric meltblown fibers, such as,
for example, polypropylene microfibers. Alternatively, the polymeric
meltblown fibers may be elastomeric polymer fibers, such as those
provided by a polymer resin. For instance, VISTAMAXX elastic olefin
copolymer resin designated PLTD-1810, available from ExxonMobil
Corporation of Houston, Tex., or KRATON G-2755, available from Kraton
Polymers of Houston, Tex., may be used to provide stretchable polymeric
meltblown fibers for the coform basesheets. Other suitable polymeric
materials or combinations thereof may alternatively be utilized as known
in the art.

[0018] The coform basesheet additionally may be constructed of various
absorbent cellulosic fibers, such as, for example, wood pulp fibers.
Suitable commercially available cellulosic fibers for use in the coform
basesheets can include, for example, NF 405, which is a chemically
treated bleached southern softwood Kraft pulp, available from
Weyerhaeuser Co. of Federal Way, Wash.; NB 416, which is a bleached
southern softwood Kraft pulp, available from Weyerhaeuser Co.; CR-0056,
which is a fully debonded softwood pulp, available from Bowater, Inc. of
Greenville, S.C.; Golden Isles 4822 debonded softwood pulp, available
from Koch Cellulose of Brunswick, Ga.; and SULPHATATE HJ, which is a
chemically modified hardwood pulp, available from Rayonier, Inc. of
Jessup, Ga. The relative percentages of the polymeric meltblown fibers
and cellulosic fibers in the coform basesheet may vary over a wide range
depending upon the desired characteristics of the wipes. For example, the
coform basesheet may have from 10 to 90 weight percent, desirably from 20
to 60 weight percent, and more desirably from 25 to 35 weight percent of
polymeric meltblown fibers based on the dry weight of the coform
basesheet.

[0019] The durable antimicrobial compositions may be incorporated into the
basesheet in an add-on amount of from 50 to 800 percent by weight of the
basesheet. More specifically, the compositions may be incorporated into
the basesheet in an add-on amount of from 200 to 600 percent by weight of
the basesheet or from 400 to 600 percent by weight of the basesheet. The
composition add-on amounts may vary depending on the composition of the
basesheet.

[0020] The present invention relates to compositions having durable
antimicrobial activity. The "durability" or "persistence" of
antimicrobial activity is descriptive of a benefit provided by the
durable antimicrobial compositions. From a cost and efficiency
standpoint, it is desirable to maintain antimicrobial activity on a
surface over a period of time with one application of a composition
rather than having to frequently apply a composition because its
antimicrobial activity rapidly dissipates. From a public health
standpoint, a durable antimicrobial composition is desirable because such
a composition is more likely to prevent microbial growth than a
composition that is weaker to begin with and a durable antimicrobial
composition introduces less liquid/material into the environment, thereby
decreasing the opportunity for microbes to develop resistance. The
durability of the compositions is measured by activity after twenty-five
(25) insults with a representative Gram negative bacterium, Escherichia
coli (E. coli). The compositions retain activity sufficient to cause a
log 2 reduction upon the twenty-fifth insult of 106 total E. coli
organisms. Additionally, the durability of the compositions is measured
by ability to effect greater log 2 reduction against Gram positive
bacteria, Gram negative bacteria, enveloped viruses, non-enveloped
viruses, fungi, mildew and mold twenty-four (24) hours after application
of the composition to a surface. Further, the durability of the durable
antimicrobial compositions is measured by ability to effect greater log 2
reduction in microorganisms in the presence of soil after either of the
first two assays described above (i.e., (1) twenty-fifth insult of
106 total organisms; or (2) twenty-four hours after application).
From a practical standpoint, a standard surface, such as a countertop,
table, telephone, etc., in a susceptible environment, such as a hospital
or daycare facility, is continuously exposed to potentially harmful
microorganisms. Given the rate at which exposure to new microorganisms
typically occurs, a durable antimicrobial composition may be applied to
the surface in a timeframe of every 24 hours to 48 hours in order to kill
and/or to prevent the growth of microorganisms. Comparatively, an
antimicrobial composition that is not durable would need to be applied
continuously to a surface to maintain a comparable level of antimicrobial
activity. In a less susceptible environment and with a less susceptible
surface, such as draperies in a home, the durable antimicrobial
composition may last up to seven days at full activity.

[0021] The durable antimicrobial compositions include a
carbonate/bicarbonate salt of a quaternary ammonium cation. Quaternary
ammonium compounds are generally considered "broad spectrum"
antimicrobial cationic compounds that have efficacy against both Gram
positive and Gram negative microorganisms. The carbonate/bicarbonate
salts of quaternary ammonium cations may be selected from
dioctyldimethylammonium carbonate, decyloctyldimethylammonium carbonate,
didecyldimethylammonium carbonate, benzalkonium carbonate, benzethonium
carbonate, stearalkonium carbonate, cetrimonium carbonate, behentrimonium
carbonate, dioctyldimethylammonium bicarbonate,
decyloctyldimethylammonium bicarbonate, didecyldimethylammonium
bicarbonate, benzalkonium bicarbonate, benzethonium bicarbonate,
stearalkonium bicarbonate, cetrimonium bicarbonate, behentrimonium
bicarbonate, and mixtures of one or more such carbonate salts. The
durable antimicrobial compositions may include from 0.2 to 15.0 percent
by weight of one or more carbonate/bicarbonate salts of quaternary
ammonium cations.

[0022] The durable antimicrobial compositions also include an organic
acid. Organic acids are also known to have efficacy against the growth of
microorganisms. The organic acid may be selected from citric, malic,
maleic, oxalic, glutaric, succinic, lactic, glycolic, fumaric, acetic,
benzoic, propionic, sorbic, tartaric, formic and mixtures of one or more
such organic acids. The durable antimicrobial compositions may include
from 0.1 percent by weight to 3.0 percent by weight of one or more
organic acids.

[0023] Additionally, the durable antimicrobial compositions include
hydrogen peroxide. The hydrogen peroxide is stable in the durable
antimicrobial compositions, despite the presence of the
carbonate/bicarbonate salt. Existing antimicrobial compositions do not
contain stabilized hydrogen peroxide in combination with a
carbonate/bicarbonate salt. The stability of the hydrogen peroxide is
measured by the durable antimicrobial compositions maintaining their
initial concentration and efficacy during shelf-life studies. For
example, the compositions remain effective (meaning, they have the same
level of durability to effect a log 2 reduction in organisms after
twenty-five insults of 106 organisms) after storage for three months
at 40° C.; further, the compositions remain effective after
storage for one month at 50° C., nine months at 25° C. and
after three freeze-thaw cycles. Specifically, the concentration of
hydrogen peroxide in exemplary compositions after various shelf-life
studies is provided in Table 1 below. The exemplary compositions in Table
1 each included the following components: (1) 2 percent by weight of
CARBOQUAT H solution as available from Lonza Group Limited Switzerland;
(2) 0.85 percent by weight of citric acid;

[0024] (3) 3 percent by weight hydrogen peroxide; and (4) 2.5 percent by
weight polyquaternium-22 polymer (MERQUAT 295 polymer available from
Nalco Company). The compositions in Table 1 also included 0.4 percent by
weight urea; further, the compositions included the indicated type and
amount of organic solvent and the remainder of the compositions was
water. Note, while an organic solvent was used for purposes of these
examples, the solvent is not needed for the compositions to have the
described efficacy and durability. In fact, before the treated surfaces
were insulted as described below, the treated surfaces were allowed to
dry and the solvent and water would have evaporated. Each of these
compositions produced the indicated log reduction of microorganisms
within five minutes after twenty-five individual insults of 106 E.
coli organisms.

[0025] The results in Table 1 show that durable antimicrobial compositions
described herein are stable as indicated by sustained presence of
hydrogen peroxide under different shelf-life study conditions.

[0026] While not wishing to be bound by theory, it is believed that the
ability to provide compositions with stabilized hydrogen peroxide
significantly expands the range of microorganisms that the durable
antimicrobial compositions are effective against. Some microorganisms
exist or are spread in spore form, where the spores have an outer layer;
the outer layer presents a barrier to penetration by some conventional
antimicrobial compositions. It is believed that the stabilized hydrogen
peroxide in the durable antimicrobial compositions is capable of
penetrating the outer layer of spores, thereby facilitating exposure of
the spore interior to the carbonate/bicarbonate salt of a quaternary
ammonium cation. The carbonate/bicarbonate salt of a quaternary ammonium
cation prevents future germination or development of the spore. The
durable antimicrobial compositions may include from 0.5 to 5.0 percent by
weight of hydrogen peroxide.

[0027] The stability of the durable antimicrobial compositions is also
measurable by the ongoing/sustained detectable concentration of the
carbonate/bicarbonate salt of a quaternary ammonium cation, organic acid
and hydrogen peroxide components of the compositions. The
carbonate/bicarbonate salt of a quaternary ammonium cation component may
be detected using high pressure liquid chromatography (HPLC) with an
evaporative light-scattering (ELS) detector. The mobile phase for the
HPLC is an acidic mixture of acetonitrile and water. The organic acid
component may be detected using HPLC with an ultra-violet (UV) absorption
detector monitoring the 220 nanometer wavelength. The mobile phase for
the HPLC for the detection of the organic acid is also an acidic mixture
of acetonitrile and water. The hydrogen peroxide component may be
detected by titrating the sample with a solution of ceric sulfate and
ferroin indicator as described in the journal article, Frank P. Greenspan
and Donald G. MacKellar entitled "Analysis of Aliphatic Per Acids"
published in Analytical Chemistry, 1948, 20, 1061. The durable
antimicrobial compositions have a sustained and detectable presence of
these components after experiencing the accelerated shelf-life conditions
described herein.

[0028] The durability of the hydrogen peroxide in the presence of the
carbonate/bicarbonate salt is provided by the polymer component of the
durable antimicrobial composition. The polymer is selected from cationic
amine polymer-epichlorohydrin adduct, cationic amine
polymer-epichlorohydrin resin,
poly(methacrylamidopropyltrimethylammonium)chloride,
poly(bis(2-chloroethyl)ether-alt-1,3-bis(dimethylamino)propyl)urea,
poly(diallyldimethylammonium)chloride, poly(t-butyl acrylate co-ethyl
acrylate co-methacrylic acid), polyethylene oxide, polyquaternium-16,
polyquaternium-22, polyquaternium-67 and mixtures of such polymers. The
durable antimicrobial compositions may include from 0.5 to 10 percent by
weight of polymer.

[0029] Additionally, the durable antimicrobial compositions also include a
compatible surfactant. The surfactant is selected from cationic
surfactants, non-ionic surfactants, zwitterionic surfactants, and
combinations thereof. The durable antimicrobial composition may suitably
include one or more compatible surfactants in an amount of from about
0.01 to about 10 percent by weight of the composition.

[0030] Compatible surfactants provide adequate stability with regard to
freeze/thaw, temperature extremes, and fragrance addition. Furthermore,
these compatible surfactants allow for basal biocide sequestration after
drying followed by a metered burst release performance upon wetting. Not
all surfactants are compatible with durable antimicrobial composition.
For example, an anionic surfactant will react with other components of
the durable antimicrobial composition to form a coacervate. This leads to
poor resistance to abrasion and poor efficacy.

[0031] As described above, the surfactant may be a nonionic surfactant.
Nonionic surfactants typically have a hydrophobic base, such as a long
chain alkyl group or an alkylated aryl group, and a hydrophilic chain
comprising a certain number (e.g., 1 to about 30) of ethoxy and/or
propoxy moieties. Examples of some classes of nonionic surfactants that
can be used include, but are not limited to, ethoxylated alkylphenols,
ethoxylated and propoxylated fatty alcohols, polyethylene glycol ethers
of methyl glucose, polyethylene glycol ethers of sorbitol, ethylene
oxide-propylene oxide block copolymers, ethoxylated esters of fatty
(C8-18) acids, condensation products of ethylene oxide with long
chain amines or amides, condensation products of ethylene oxide with
alcohols, and combinations thereof.

[0033] Additional nonionic surfactants that can be used include water
soluble alcohol ethylene oxide condensates, such as the condensation
products of a secondary aliphatic alcohol containing between about 8 to
about 18 carbon atoms in a straight or branched chain configuration
condensed with between about 5 to about 30 moles of ethylene oxide. Such
nonionic surfactants are commercially available under the trade name
Tergitol from The Dow Chemical Company (Midland, Mich.). Specific
examples of such commercially available nonionic surfactants of the
foregoing type are C11-15 secondary alkanols condensed with either 9
moles of ethylene oxide (Tergitol 15-S-9) or 12 moles of ethylene oxide
(Tergitol 15-S-12) marketed by The Dow Chemical Company (Midland, Mich.).

[0034] Other suitable nonionic surfactants include the polyethylene oxide
condensates of one mole of alkyl phenol containing from about 8 to 18
carbon atoms in a straight or branched chain alkyl group with about 5 to
30 moles of ethylene oxide. Specific examples of alkyl phenol ethoxylates
include nonyl condensed with about 9.5 moles of ethylene oxide per mole
of nonyl phenol, dinonyl phenol condensed with about 12 moles of ethylene
oxide per mole of phenol, dinonyl phenol condensed with about 15 moles of
ethylene oxide per mole of phenol and diisoctylphenol condensed with
about 15 moles of ethylene oxide per mole of phenol. Commercially
available nonionic surfactants of this type include Igepal CO-630 (a
nonyl phenol ethoxylate) marketed by ISP Corp. (Wayne, N.J.). Suitable
non-ionic ethoxylated octyl and nonyl phenols include those having from
about 7 to about 13 ethoxy units. Such compounds are commercially
available under the trade name Triton X by The Dow Chemical Company
(Midland, Mich.).

[0035] Alkyl polyglycosides may also be used as a nonionic surfactant in
the durable antimicrobial composition. Suitable alkyl polyglycosides are
known nonionic surfactants that are alkaline and electrolyte stable.
Alkyl mono and polyglycosides are prepared generally by reacting a
monosaccharide, or a compound hydrolyzable to a monosaccharide with an
alcohol such as a fatty alcohol in an acid medium. Commercially available
nonionic surfactants of this type include Glucopon 425 marketed BASF
(Ludwidschafen, Germany).

[0037] In addition to the components described herein, the durable
antimicrobial compositions may also include a polar carrier solvent, pH
adjuster, fragrance, preservative, dye, corrosion inhibitor, builder,
cleansing solvent, and other components known to be useful in
antimicrobial compositions. The durable antimicrobial compositions may
include from 67 to 98 percent by weight of one or more of these other
components.

[0038] While other blending methods may be used, an example of one method
of blending the durable antimicrobial compositions is as follows: (1) Add
water to vessel for mixing of the components of the compositions; (2)
Slowly add the carbonate/bicarbonate salt of the quaternary ammonium
cation component to the vessel; (3) Slowly add the organic acid component
to the vessel and begin mixing at low revolutions per minute (RPM) (i.e.,
150-250 RPM); (4) Continue mixing until any foam that is present
dissipates (e.g., up to 10 minutes for a 1 liter batch); (5) If desired
for additional stability when the final composition is applied to a
surface, add a stabilizer such as urea and continue mixing at low RPM
(e.g., add 0.4 percent by weight of urea if adding 3.0 percent by weight
hydrogen peroxide); (6) Slowly add hydrogen peroxide to the vessel and
continue mixing at low RPM; (7) Slowly add the polymer component to the
vessel and continue mixing at low RPM; (8) If desired for solution
clarity, an appropriate organic solvent (e.g., ethanol, isopropanol,
ethylene glycol, propylene glycol, butylene glycol, ethylene glycol
monobutyl ether, etc.) may slowly be added to the vessel; and (9) If
necessary, adjust the pH of the final composition in the vessel to pH 3.0
(+/-0.25) with a dilute (10 to 25 percent by weight) solution of
potassium hydroxide. Those of skill in the art will appreciate that there
are other methods by which the components of the durable antimicrobial
compositions may be blended. However, it is an aspect of the present
invention that the carbonate/bicarbonate salt of the quaternary ammonium
cation is neutralized by the addition of the organic acid in step 3 prior
to the addition of the hydrogen peroxide.

[0039] Representative examples of the polymers of the durable
antimicrobial composition are provided in Table 2 below. Each exemplary
polymer described in Table 2 was used in a durable antimicrobial
composition that included the following components: (1) 2 percent by
weight of CARBOQUAT H solution as available from Lonza Group Limited
Switzerland; (2) 0.85 percent by weight of citric acid; and (3) 3 percent
by weight hydrogen peroxide. The compositions also included 0.4 percent
by weight urea and 20 percent ethanol; the remainder was water. Note,
while ethanol was used for purposes of these examples, the ethanol is not
needed for the durable antimicrobial compositions to have the described
efficacy and durability. In fact, before the treated surfaces were
insulted as described below, the treated surfaces were allowed to dry and
the ethanol and water would have evaporated. Similarly, while not
required, the urea is added to provide enhanced stability of the
compositions after application to a surface. Each of these compositions
produced the indicated log reduction of microorganisms within five
minutes after twenty-five and/or fifty individual insults of 106 E.
coli organisms.

[0040] The "no data" designations indicate insult conditions that were not
tested either because (i) the polymer at a lower wt. % already
demonstrated at least a log 3 reduction after twenty-five insults or (ii)
the polymer demonstrated close to a log 2 reduction after twenty-five
insults and therefore, was unlikely to demonstrate a log 2 reduction
after fifty insults.

[0041] In addition to the log reduction data for the durable antimicrobial
compositions provided in Table 2 above, stability data for some of the
compositions is provided in Table 3 below. Stability is demonstrated by a
continued presence of hydrogen peroxide in the compositions after
exposure to different shelf-life conditions. Each of the compositions in
Table 3 contained components similar to those described for the
compositions of Table 2.

[0042] The results in Table 3 show that the durable antimicrobial
compositions are stable as indicated by sustained presence of hydrogen
peroxide under different shelf-life study conditions.

[0043] Samples were also prepared to illustrate the stability of the
composition with a surfactant included. To show stability, tests were run
to determine the release profile of different biocides contained in
exemplary durable antimicrobial formulations on hard surfaces and the
durability of the films obtained from such formulations. To illustrate
the release profile of the various compositions, sample compositions were
prepared as described below. To test durability, pre-weighed substrates
were placed in a fume-hood and 80-microliters of durable antimicrobial
formulation was dispensed on top of each substrate spreading the
formulation across the entire surface. The substrate is a non-porous,
pre-cleaned, passivated 1 inch by 1 inch piece of stainless steel (18 ga
304 sst with mirrored finish). Substrates were passivated by immersing
substrates in the Carboquat-H 3 wt. % solution for 2 hours; immersing
them in the citric acid 3 wt. % solution for 2 hours and rinsing
substrates twice by immersing them in clean DI-water for 30 minutes; and
immersing them in the 3 percent hydrogen peroxide solution for 2 hours
and rinsing the substrates twice immersing by them in clean DI-water for
30 minutes. After application of the formulation, the substrates were
dried for 14 hours and then weighed to determine the weight of the film.

[0044] The substrates were extracted with 1.2 mL of DI water in a weighing
dish placed on orbital-shaker (IKA Shuttler MTS4). The substrate is
placed into the DI water with the polymer film facing the weighing dish,
in the water and the speed of the orbital shaker is set to 100. Aliquots
of 300 microliters each of the extraction fluid are then transferred to
HPLC vials at 15 seconds, 30 seconds, 1 minute, 2 minutes and 7.5
minutes. An HPLC system with UV- and ELSD-detectors; and a Neptune Hilic
Silica Column (5μ 100 A; 15 cm by 4.6 mm) from ES-Industries (Cat.
#135221-NPN-SI) was used to determine the amount of the biocide released
from the system at each time. The UV-Detector was set at 195 nm and the
ELSD-Detector was set at a gas flow of 0.6, with a Neb. Temperature of
100° C. and an Evap. Temperature of 80° C. The gradient was
set at 0.08 percent TFA with an injection volume of 10 μL.

[0045] Representative examples of a surfactant of the durable
antimicrobial composition are provided in Table 4 below. Each exemplary
surfactant described in Table 4 was used in a durable antimicrobial
composition in a concentration of 1.0 percent active surfactant by weight
that included the following components: (1) 2 percent by weight of
CARBOQUAT H solution as available from Lonza Group Limited Switzerland;
(2) 0.85 percent by weight of citric acid; (3) 3 percent by weight
hydrogen peroxide; and (4) 2.5 percent by weight polyquaternium-22
polymer (MERQUAT 295 polymer available from Nalco Company). The
compositions also included 0.4 percent by weight urea and 20 percent
ethanol; the remainder was water. Table 4 also illustrates the biocide
release of various actives of the durable antimicrobial compositions.

[0046] The durable antimicrobial compositions including the exemplary
surfactants represented in Table 4 have a similar release profile of
biocide and similar durability described for the exemplary durable
antimicrobial composition not including a surfactant in Table 4. All of
the durable antimicrobial compositions including the exemplary
surfactants had quick release of the citric acid and CARBOQUAT H compound
illustrating the compositions are stable and similar durability required
of the durable antimicrobial composition described herein.

[0047] While the compositions of the invention have been described in
detail with respect to specific aspects thereof, it will be appreciated
that those skilled in the art, upon attaining an understanding of the
foregoing, may readily conceive of alterations to, variations of and
equivalents to these compositions. Accordingly, the scope of the present
invention should be assessed as that of the claims and any equivalents
thereto.